That's right, Grohl in his Foo Fighting rock majesty likely could have been backstage mucking it up with the band or in a VIP suite somewhere else in the building, but the former Nirvana drummer and Foo Fighters frontman found his way into the pit to take in the thunder that comes with a Metallica show.

Even rock stars need to rock out off stage sometimes, I guess. Maybe he was just there for Lars' drumming.

The new Foo Fighters Album, Concrete and Gold, will be released on September 15 and features their new song "Run," which you can listen to below.